Location

New York, New York

Session Start Date

4-13-2004

Session End Date

4-17-2004

Abstract

Centrifuge models representing level uniform saturated deposits of relatively loose and dense sand were tested at Cambridge University's Schofield Centre to clarify the behaviour of these deposits under earthquake loading. The excess pore pressure, vertical propagation of the accelerations and ground surface settlements resulting from a model earthquake are presented and discussed. The results show that, for similar dynamic loading, the models undergo large shear stiffness degradation resulting from significant pore pressure build up, this taking place at a slower rate in the dense sand. As a result of the cyclic loading, the models suffer settlements, occurring mostly during the event, that are noticeably smaller in the dense model. The upwards propagation of the accelerations through the model depends on the relative density of the sand and changes during the seismic event, following degradation of sand mechanical properties. Large short-duration acceleration spikes are observed near the surface of the dense model, corresponding to large amplification of input acceleration. The results presented and discussed contribute to the understanding of the basic mechanisms of earthquake-induced liquefaction and the use of densification as a measure to mitigate its effects.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fifth Conference

Publisher

University of Missouri--Rolla

Publication Date

4-13-2004

Document Version

Final Version

Rights

© 2004 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 13th, 12:00 AM Apr 17th, 12:00 AM

Centrifuge Modelling of Earthquake Effects in Uniform Deposits of Saturated Sand

New York, New York

Centrifuge models representing level uniform saturated deposits of relatively loose and dense sand were tested at Cambridge University's Schofield Centre to clarify the behaviour of these deposits under earthquake loading. The excess pore pressure, vertical propagation of the accelerations and ground surface settlements resulting from a model earthquake are presented and discussed. The results show that, for similar dynamic loading, the models undergo large shear stiffness degradation resulting from significant pore pressure build up, this taking place at a slower rate in the dense sand. As a result of the cyclic loading, the models suffer settlements, occurring mostly during the event, that are noticeably smaller in the dense model. The upwards propagation of the accelerations through the model depends on the relative density of the sand and changes during the seismic event, following degradation of sand mechanical properties. Large short-duration acceleration spikes are observed near the surface of the dense model, corresponding to large amplification of input acceleration. The results presented and discussed contribute to the understanding of the basic mechanisms of earthquake-induced liquefaction and the use of densification as a measure to mitigate its effects.